The next hundred years of growth and convergence

World gross domestic product per capita is forecast to grow at 2.6% annually over the next 100 years. Convergence of less-developed countries toward output levels of the world frontier accounts for much of the forecast. Projecting recent growth in China and India accounts for much of the forecast convergence. The forecast differs from the earlier literature because the facts of convergence have changed in recent decades. A Markov-switching model is estimated for each country, allowing each country to switch on or off a path of convergence to the world output frontier. Bayesian estimates of the historical process and posterior forecasts are offered.